The effect of assessment management and selecting the appropriate contractor is growing interest in research because of the change in preferences of contractors’ behaviour and the growth of competitiveness. The assessment of contractors is a continuous process that demands ongoing monitoring to maintain high quality ranks. In this study, the factors behaviour of contractors' assessment for a construction engineering company and a method of topological analysis are examined to a) aid in the interpretation of existing relationships among all factors and b) find influencing factors of contractors’ assessment. The method begins with the network construction of factors considering some criteria or standards. We then propose a method of network analysis and describe the results of studies undertaken to apply the correlation network-based approach and discuss the implications of the methodology. As a result of this study, all influencing factors are involved in a category. The most influential factor is the specialized training of staff that can improve the contractors' productivity and competitiveness.